Root plasticity maintains growth of temperate grassland species under pulsed water supply
Root plasticity maintains growth of temperate grassland species under pulsed water supply
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DOI：
10.1007/s11104-012-1584-x
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发表时间：
2013-01
期刊：
影响因子：
4.9
通讯作者：
F. M. Padilla;Bart H. J. Aarts;Yvonne O. A. Roijendijk;H. Caluwe;L. Mommer;E. Visser;H. Kroon
中科院分区：
文献类型：
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作者：
F. M. Padilla;Bart H. J. Aarts;Yvonne O. A. Roijendijk;H. Caluwe;L. Mommer;E. Visser;H. Kroon
在高纬度地区，降雨的频率预计会发生变化，在较长的干旱期中，降水量会增加。这些变化将修改土壤干燥周期与未知的后果，为植物性能的温带species.MethodsWe研究了植物生长和根系性状的青少年的四个草和四个双子叶植物生长在温室中，当供应相同的总水量给予定期每隔一天或脉冲一周once.ResultsPulsed供水补充土壤水分后立即浇水，但在浇水周期结束时造成了严重的干旱胁迫，而定期浇水造成了更温和但持续的干旱。脉冲灌溉下牧草的水分利用效率低于常规灌溉，而双子叶植物的水分利用效率无明显差异。在脉冲供水条件下，禾本科植物和双子叶植物的根均较细，比根长较高，根长也较大。双子叶植物的生长略有增加下pulsed watering.ConclusionsTemperate物种应付脉冲供水引起两个响应：i）持久的芽生长，最有可能通过最大限度地提高增长在土壤水分的峰值，从而弥补在干旱期间增长缓慢; ii）可塑性的根性状增加资源的吸收。这两种反应可能占微妙的改善增长变化供水条件下。
Background and aimsThe frequency of rain is predicted to change in high latitude areas with more precipitation in heavy, intense events interspersed by longer dry periods. These changes will modify soil drying cycles with unknown consequences for plant performance of temperate species.MethodsWe studied plant growth and root traits of juveniles of four grasses and four dicots growing in a greenhouse, when supplying the same total amount of water given either regular every other day or pulsed once a week.ResultsPulsed water supply replenished soil moisture immediately after watering, but caused substantial drought stress at the end of the watering cycle, whereas regular watering caused more moderate but consistent drought. Grasses had lower water use efficiency in the pulsed watering compared to regular watering, whereas dicots showed no difference. Both grasses and dicots developed thinner roots, thus higher specific root length, and greater root length in the pulsed watering. Growth of dicots was slightly increased under pulsed watering.ConclusionsTemperate species coped with pulsed water supply by eliciting two responses:i)persistent shoot growth, most likely by maximizing growth at peaks of soil moisture, thus compensating for slower growth during drought periods; ii) plasticity of root traits related to increased resource uptake. Both responses likely account for subtle improvement of growth under changed water supply conditions.